Pin message

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate this is not read-only (readOnlyHint: false). The description adds useful behavioral context beyond annotations: the specific permission required and the channel's maximum pin count. It does not contradict the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three short sentences with no redundancy. The first sentence is the core purpose, and the following sentences add relevant constraints (permission, pin limit). Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple pin operation, the description covers the essential context: purpose, permission requirement, and the 50-pin limit. It does not explain edge cases like duplicate pins or behavior when the limit is reached, but the tool is simple enough that this is acceptable given the annotations and schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 50%, with guild and channel described. The description does not add parameter-specific details for reason or message_id, but these are self-explanatory. The description adds minimal parameter semantics beyond what the schema provides, so a baseline score of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description begins with 'Pin a message in a channel,' which is a specific verb+resource construction. It clearly distinguishes from sibling tools like unpin_message and list_pinned_messages by focusing on the act of pinning.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear context for when the tool is applicable by stating the required permission and the 50-pin limit. It does not explicitly mention alternatives or when not to use it, but the sibling names make the distinction obvious, so no exclusions are needed.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.